Rock drilling apparatus



1 7 I N. E. WOLFRAMI- 2,812,163

ROCK DRILLING APPARATUS Filed March 24, 1955 I 2 Sheets-Sheet 1 I luv INVENTOR. NORMAN E-WOI F'RAM v ATTOR N EYS Nov. 5, 1957 N. E. WOLFRAM ROCK DRILLING APPARATUS 2 Sheets-Sheet 2 Filed March 24, 1955 IIHI INVENTOR NORMAN E. WOLF'RAM BY ATTSRNEYS 2,812,163 ROCK DRILLING APPARATUS Norman E. Wolfram, South Deerfield, Mass. Application March 24, 1955, Serial No. 496,371

Claims. (Cl. 255-49) This invention relates to drilling apparatus and particularly to a coupling device for fixing a drill steel and a casing sleeve to a rock drilling hammer for sleeve conduit boring. A particular object is to provide apparatus for coupling a drill steel and encasing sleeve of the type in which provision is made to remove material dislodged by the bit of the drill by a flow of water under pressure.

The drilling apparatus for Which the coupling device is particularly designed is used in forming a passage through deposited or natural earth formations comprised in part or entirely of rocks, ledge stone, stone or gravel fill, etc., where a cylindrical casing is fed through the hole made by the drill bit for a sleeved conduit as may be desired. An example may be found in boring work required to form an encased passagefor placing a water pipe or gas line under a highway or railroad track bed.

In the drilling operation a section of the rod or drill steel with a sleeve encasing the same is attached to the drilling apparatus in which the new coupling device is used. At the front end of the sleeve and, fixed to the end of the rod, a bit extends to drill a hole ahead of the casing. The drill steel i percussively actuated and revolved step by step as in the conventional type of rock drilling hammer. As the hole is formed the hammer is fed forwardly in the direction desired into the material being drilled until the casing becomes substantially embedded, and the outer end thereof is adjacent the entrance of the hole. The casing and rod are then disconnectedfrom the hammer ram, the hammer is retracted, and suitable extensions of the drill rod and easing are inserted between the exposed ends of the previously embedded sections and the retracted rain. The drilling operation continues as described and as many extensions as are necessary to complete the conduit are added until the drill bit and casing emerge at the other end of the hole. The bit is removed from the rod and the rod is then removed from the sleeve. The sleeve is left in place to form the conduit for the desired purpose.

The object of the present invention is to provide a coupling device for drilling apparatus of the above type which will enable the convenient insertion of additional sleeve and rod extensions so as to proceed with the boring operation with the least amount of interruption.

Another object of the invention is to provide a coupling device which will efiiciently deliver a supply of water under pressure to a rotatable and reciprocably driven drill ro'd, the lattersupplying a passagefor the Water feed, and to provide for the convenient removal of drillings by wash water carrying the material dislodged by the drill bit backthrough the annular passage between the rod and sleeve.

Another objectof the invention is to provide a coupling device adapted for use with casing sleeves of various dianieter's.

Additional objects and advantages will be-apparent from the following descriptionof an embodiinen't'of the invention slidwn by the attached drawingg'in which arent Fig. 1 is a side view of a drlling apparatus embodying the invention;

Fig. 2 is a section on line 22 of Fig. 1;

Fig. 3 is a section on line 33 of Fig. 1;

Fig. 4 is a vertical sectional view showing details of the coupling device shown in the apparatus of Fig. 1

Fig. 5 is an end view of the coupling device looking in the direction of line 5-5 of Fig. 4; and

Fig. 6 is a plan view of the end of the coupling device looking in the direction of line 6-6 of Fig. 5.

In Fig. 1 a drill rig of the t-ype'in which the coupling device may be used is shown with a rock bit 1 fixed at the end of a section of drill steel as the rod 2, the rod being concentrically disposed in a section of the casing sleeve .3 adapted to follow the bit into the hole being drilled and form theconduit desired. It will be understood that in starting the bit to form the entrance to a bore the outer end of the sleeve may be supported in any suitable manner and where the bit has once entered the earth the sleeve 3 and rod 2 will be supported thereby during further drilling. The bit 1 has a central passage and outlet at 4 leading to the front face of the bit. Rod 2 and bitl, as will be later described, are designed to feed a stream of water under pressure to the Working face of the bit through outlet 4 so as to wash the material, as dirt, gravel or stone chips, dislodged by the bit, back through the annular passage 5 of the sleeve 3. I

The drill rod and sleeve are attached attheir inner ends to a coupling apparatus, indicated generaly by numeral 6, the casing or housing of of the latter being at.- tached to the front end of a pneumatic hammer cylinder 7 as will belater described in detail. The hammer cylinder 7, having a flexible hose inlet line at 8, is a conventional type adapted to cause through its rain a percussive hammering ofthe steel and bit to drill the hole desired. It also is adapted to rotate the rod in step by step fashion during the hammering operation.

The hammer is suitably mounted on a carriage plate 9 as by a support member 7' welded to the underside of the hammer cylinder and to the plate. Plate 9 is slidably carried at the top of a pair of laterally spaced channel irons 10 forming an elongated track along which the hammer may be propelled back and forth. On its forward movement the hammer carries the drill rod and sleeve into the hole being drilled. On its rearward movement the coupling device is disconnected from the rod and sleeve and the hammer is retracted to provide the spacing for inserting additional sections or extensions of the rod and sleeve so as to continue the drilling operation. The track may therefor be on the order of 2 to 8 feet in length or longer as may be desired.

As shown by Figs. 2 and 3 the edges of the plate 9 are received in ways formed as indicated at '11. 'On the underside of the plate at the front and rear ends thereof are spaced anchoring blocks 12 and 13 (Fig. 1) to which sprocket chains 14 and 15 are fixed. The chains 14 for rearward movement of the plate are rearwardl'y looped around a pair of sprockets 16.v Chains 15 for forward movement are forwardly looped around a pair of sprockets 17. The sprockets 16 and 17 are mounted for rotation of each pair together on cross'niembers 18' and 19 and linked by a connecting rod arrangement for forward and reverse travel by meansof a piston rod 20 .of adouble' acting hydraulically operated cylinder '21 having fluid connections at 21a and 21b. The cross member 18 is underslung to pass underneath the cylinder. The other ends of chains 14 and 15 are suitably anchored, as at 22 and 23, to a bottom plate 24 positioned'between the channel irons 10.

The'connecting rod arrangement as shown may consi'st of connecting rods 25 slidably held on each "side wall between 'verticallyspaced flanged strips 26. At eac'hen'd of the rods 25 are sockets 27 for insertion of the ends 28 of the cross members. The outer end of rod 20 is fixed as by welding to the center of cross member 19. Thus movement of cross member 19 by the rod 20 of cylinder '21 moves the cross member 18 in unison with it. Hence, forward extension of rod 20 causes chain to draw the plate 9 forwardly on the track (chain 14 and sprockets 16 follow). Retraction of rod 20 causes chain 14 to pull the plate 9 rearwardly on the track (chain 15 and sprockets 17 follow). 7

An enclosure providing mounting means for the cylinder 21 is indicated at 29 with a housing for the controls of the apparatusbeing indicated at 30. The drill rig as described is adapted for transportation as a unit to the 10- cationwhere the drilling is desired. It is placed in position and connected with a suitable portable source of powerand a water supply for the operation as above described.

Referring now to the coupling structure indicated at 6 in Fig. 1 and shown in detail by Figs. 4-6, it will be seen that a cylindrical housing 31 is fixed at the front end of the hammer cylinder 7. In the structure as shown the hammer cylinder 7 is provided with rods one of which is shown at 32 passing through fixed ears as at 33. The threaded end of a rod 32 is extended through a fastener nut 34 and beyond the same. Nut 34 thus provides an abutment for a flanged collar 35. The collar is slipped over the forward nose of the hammer cylinder and onto the rods 32. Being seated against the nuts 34 the collar is then rigidly fastened by nuts threaded on the end of rod 32 as at 36.

The housing 31 is rigidly fixed to the hammer cylinder by means of rods 37 extending between a forward end plate 38 (in which the ends at 39 are fixed) and the flange 35. The rods are drawn tight by nuts at 40 drawing an interior housing abutment wall at 41 against the face of the hammer. The .wall 41 is inwardly spaced from the rear openend of the housing and is provided with a central opening 42 through which a hammer ram member 43 is extended. The ram member 43 extends axially through the housing and through a central opening at 44 in the end plate 38,.

As -will be understood by those skilled in the art, the ramrnember of a conventional drill hammer cylinder may be provided witha longitudinal passage for air under pressure so as to connect with a passage in the drill steel or rod connected to the ram member and leading to the bit at the end of the steel. This air is used to blow out drillings from a hole. Since water is being employed to wash out drillings in the use of apparatus being described the ram member 43 is provided forwardly adjacent the cylinder end with a solid body portion and an outer body portion formed with a central longitudinal bore or passage 46 leading to the forward end thereof. From the inner end of the passage 46 radially directed passages as inlet ports are provided to the exterior wall of the member as shown at 45. Surrounding theram member 43 in the area of the ports 45 is a jacketed connector 47 in which an interior cylindrical chamber 48 is formed to lie in spaced relation to the wall of the. member 43. The annular chamber formed by wall 48 and the ram member is an inlet chamber leading to the ports 45. The connector 47 as shown is mounted with its end rotatably embracing the ram member 43 at longitudinally spaced locations to enclose the inlets 45 between said ends. Each end section of connector-47 is provided with O-rings as indicated at 55 to prevent leakage from the annular chamber.

' As will also be understood by those skilled inthe .art the inner end of the ram member 43 comprising the solid body portion thereof, is inserted in the cylinder 7 in a conventional manner to 'be percussively'and rotatatively' driven by the same. The connector member 47 is held against rotation as the ram rotates by an inlet stem member as will be described. The inlet for the chamber at 48 is provided by a passage 49 in communication therewith and formed in a stern conduit 50. The stem 50 is connected to a flexible hose 51 for supply of water under pressure to the passage 46. The stem 50 extends through an elongated slot 52 of the housing and a slot cover plate 53 spring-held on the upper surface of the housing by a spring 54. The stem can thus move back and forth during the reciprocatory percussive movement of the hammering action of the ram member 43 and connector 47. Since the housing 31 is stationary and the stem 50, which is connected to the chambered connector 47, extends through the housing, the stem 50 prevents rotation of connector 45 on the rotatable ram member, which as previously noted is rotated in the conventional manner during its hammering strokes. Rubber bumpers 56 are also provided around the ram at each end of the connector 47.

In the lower wall of the housing is an outlet port 57 for the wash water and drillings returned from the sleeve through the opening 44 of the wall 38 as indicated by the arrows.

The outer face of the end wall 38 is formed with concentric forwardly extending rings 59 formed with lands 60 to receive, as shown on the innermost ring the split halves of a sleeve connecting clamp indicated by the numeral 61. The halves 62 of the clamp are grooved to fit the lands 60 with the inner clamp end seated against the wall 38 with a spacer member 63 abutting the end of the ring.

Against the outer edges of the spacers 63 the inner end of sleeve casing 3 is seated and when the bolts 64 (Figs. 5 and 6) are tightened to draw the halves into clamped relation the sleeve is held thereby for pushing the sleeve into the hole formed by the bit. A sleeve set screw 3' is also provided in the upper section of the clamp wall to further assist in rigidly anchoring the sleeve and coupling together.

The outer. end of the ram member 43 is fitted with a connector 65 which has an outer threaded end with which the inner threaded end of rod 2 is mated by a pipe connector 66. The connection of the drill rod and ram member is positioned within the sleeve coupling 61. The drill rod 2 is also provided with a central passage 67 communicating with passage 46 of the ram member and the outlet 4 of the bit as shown by Fig. 1.

From the description previously given with respect to the operation of the drilling apparatus shown by Fig. 1, it will be appreciated that the drill steel may be thrust into the'hole formed by the bit and the sleeve pushed simultaneously with it by the forward travel of the hammer cylinderon the carriage plate 9. At the beginning of drilling operations the piston rod 20 (Fig. 1) is in a rearward position with the plate 9, hammer cylinder 7, and coupling device 6 is a rearward position on track 10. As the drilling proceeds, the steel rod 2 (within sleeve 3) is rapidly reciprocated according to the conventional action of the ram member. The repeated blows imparted to the bitbeyond the end of sleeve 3 cause a wearing away and removal of the material against which it is thrust. Wash water simultaneously with the ram action is fed (Fig.4) through hose 51, passage 49, chamber 48, inlet 45, passages 46 and 67 to outlet 4 (Fig. 1). The material loosened or cut away by the bit is washed by the force of the water under pressure from the outlet 4. The drillings are conveyed back through the sleeve 3, the particular details for accomplishing this being immaterial to the present invention. The wash water is conveyed from the sleeve as indicated by the arrows and conveniently dumped out through a lower port of the housing as 'at 57." If desired the washed drillings can, of course, be suitably confined beyond the housing for disposition at a more remote location. As the bitwears away the earth, rock, etc., the piston rod 20 is. slowly extended to carry the cylinder 7, coupling device 6;

sleeve 3, and steel 2 forwardly in the direction of the hole being drilled. This forward motion results in the bit progressively forming the hole with the outer end of the sleeve following closely behind the bit. The carriage on track provides simultaneously with the percussive action a forward movement of the steel, sleeve, and hammer to maintain the bit against the working surface and the sleeve back of it.

When the forward end of the unit 6 is adjacent the entrance of the hole and the sleeve section 3 is substantially embedded therein, the disconnection of the drill steel and sleeve can be quickly accomplished. The sleeve coupling 61 is first removed to expose the rod connector 66. The housing 31 and ram member 43 then can be backed off slightly without the sleeve so as to disconnect the member 65 from the pipe connector 66. Next the hammer cylinder 7, ram member 43 and housing 31 may be retracted to the rearward end of the track. Another section of drill steel 2 with a sleeve section slidably encasing the same is then joined at one end to the free end of the embedded section and at its opposite end linked to the connector 66. The sleeve section being somewhat shorter than the steel is Welded at its outer end permanently to the-exposed end of the embedded sleeve 3. At its inner end the new sleeve section can then be rigidly fixed relative to the ring 59 by the split clamp 61.

The drilling proceeds as before. Suitable clamps 61 of a larger diameter may, of course, be provided to fit the outer rings 59 for a larger diameter of sleeve. The same coupling device may thus be equipped for drilling operations with various size'bits and casing sleeves.

When the bit 1 emerges at the far side of the earth formation or other obstruction through which it has drilled, the bit 1, as previously stated, is removed from the end of the steel 2. The sleeve 3 is then uncoupled from its clamped relation on the housing 6 and the steel 2 is withdrawn from the sleeve. The sleeve 3 is left in the earth and thus provides a conduit casing through which-piping, wiring, etc., may be passed.

What is claimed is:

1. Drilling apparatus comprising a rock drilling hammer having a ram member extending from the hammer and formed with an outer end portion having a longitudinal bore in said outer end portion, the inner end of said bore having a passage leading therefrom to the exterior of said ram member, an inlet conduit member encasing said ram member and having a chambered portion around the ram member in the area of said exterior passage, said ram member being rotatable relative to said conduit member, and, at its outer end having removable connector means for connecting a section of longitudinally bored drill steel in end to end abutting relation therewith, a housing rigidly fixed on said drilling hammer extending in spaced surrounding relation to said ram member with said connector means of the ram member being outwardly of the end of said housing, said housing having means holding said chambered conduit member against rotation of the latter with said ram member and an outlet port for discharge of fluid fromthe interior of the housing, drill steel sleeve clamping means removably mounted at the outer end of said housing for mounting the end of a casing sleeve in rigid relation to the housing, said clamping means and outer end of the housing being in spaced surrounding relation to said outer end of the ram member and forming an annular passage therebetween to the interior of said housing.

2. Drilling apparatus comprising a rock drilling hammer, a housing rigidly fixed at the front end of said hammer and forming a cylindrical chamber extension thereof, a hammer ram member passing through said chamber, said ram member having a longitudinal bore therein with the inner end of the bore spaced from the front end of the hammer and having transverse passages communicating with the exterior wall of said ram member, an inlet conduit member including a jacketing element rotatably surrounding said ram member within said housing chamber and forming with said exterior wall of the ram member an annular inlet chamber, said latter chamber being in communication with said transverse passages, a rigid inlet conduit extending radially of said housing chamber from said jacketing element, the wall of said housing having an opening receiving said conduit for passage therethrough and for maintaining said jacket against rotation with said ram member, said housing at the outer end thereof having removable clamping means for attaching a drill casing sleeverigidly therewith, and said ram member having connector means for fixing a section of drill steel in end to end abutting relation with the ram member and in inner spaced relation to said clamping means and forming therewith an annular passage communicating with said cylindrical housing.

3. The combination of claim 2 in which said housing is provided with a front wall having a central opening in spaced relation to said ram member and a cylindrical forwardly flanged portion on which said removable clamping means is affixed, and said latter means is a longitudinally split cylindrical member having abutments on the inner wall surfaces for end to end engagement with the inner end of 'a casing sleeve.

4. The combination of claim 3 in which the engaging surfaces of said housing flange and said split cylindrical member are provided with mating lands and grooves.

5. In drilling apparatus having a rock drilling hammer and conveyor means carrying the same for forward drilling movement and for withdrawal of said hammer on completion of a drilling stroke, a coupling device for the successive attachment of a plurality of sections of drill steel and casing sleeve sections surrounding the steel, said device comprising a housing fixed at the front of said hammer and constituting a hollow cylindrical extension of the same, a ram member extending therethrough and having drill steel connector means at its outer end outwardly of said housing, said ram member having a bore longitudinally thereof from its front end to a location within said housing forwardly of the hammer end with passages communicating transversely to the exterior of said member, a cylindrically formed jacket having its ends embracing said ram member at opposite :sides of said exterior passages and receiving said member for rotation in the ends of the jacket, the interior wall of said jacket between its ends being in spaced relation to the ram surface and providing an annular inlet chamber for said ram passages, an inlet conduit on said jacket directed radially of said housing and a longitudinally slotted opening in said housing receiving said conduit, a plate closely embracing said conduit and slidably covering said slot on the outer surface thereof for permitting limited reciprocation of said ram and jacket members, said housing having an outlet port in the lower section thereof and removable clamping members at the front end thereof for the annularly spaced mounting of a casing sleeve concentrically with a drill steel fixed to the ram member, said member being in surrounding relation to said connector means and having abutments outwardly thereof for engagement with the inner end of a casing sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 1,285,712 Hughes Nov. 26, 1918 1,295,320 Humphryes Feb. 25, 1919 1,684,582 Hoaglund "Sept. 18, 1928 1,704,053 Miller Mar. 5, 1929 2,588,068 Williams et al. Mar. 4, 1952 2,638,325 Joy Mar. 12, 1953 

